In direction finding, it is of great importance to quickly determine an accurate direction of an incoming electromagnetic signal. In order to do so, a number of antennas are grouped to an antenna system and receive the electromagnetic signal. From the signals received by the different antennas of the antenna system, the direction can be determined. The higher the number of antennas used, the higher the accuracy of determining the direction of the electromagnetic signal usually is. On the other hand, with an increased number of antennas, the computational complexity and general hardware complexity rises significantly.
Especially in real-world environments, a number of problems can occur, which lead to direction finding errors. For example, the incoming electromagnetic signal can experience scattering or fading. This leads to a reception of multiple signals from slightly different directions. Also, depending upon the wave length of the incoming electromagnetic signal and the positioning of the antennas, direction ambiguities are possible.
For example, the international patent application WO 2014/135196 A1 shows such a direction finding system.
There is an object to improve the accuracy of direction finding while at the same time keeping the hardware effort and the computational complexity manageable.